Americans consume too much sugar, and our collective sweet tooth has become deadly. The biggest study of its kind suggests that too much sugar can be fatal — at least when it comes to heart problems.

And it doesn’t take all that much extra sugar, hidden in many processed foods, to substantially raise the risk, researchers found. Most Americans eat more than the safest amount.

“Too much sugar does not just make us fat; it can also make us sick,” wrote Laura Schmidt, a professor of health policy at the University of California School of Medicine in San Francisco. It may contribute to deadly heart problems, high blood pressure and inflammation.

Researchers found that 71.4 percent of adults get more than the recommended 10 percent of daily calories from added sugars in foods and drinks. For someone who normally eats 2,000 calories daily, even two 12-ounce cans of soda ­substantially increases health risks.

Lead author Quanhe Yang of the U.S. Centers for Disease Control and Prevention called the results of a study published in JAMA Internal Medicine sobering and the first nationally representative attempt to examine the issue.

Scientists aren’t certain exactly how sugar may contribute to deadly heart problems, but it has been shown to increase blood pressure and levels of unhealthy cholesterol and triglycerides, and also may increase signs of inflammation linked with heart ­disease, said Rachel Johnson, head of the American Heart Association’s nutrition committee.

Video (00:29): Making the sugar illustration

Heart disease, which can cause heart attacks, chest pain and heart failure, is the leading cause of death worldwide for men and women, killing more than 600,000 Americans each year, according to the CDC.

Link found even in normal weight

Previous studies have linked diets high in sugar with increased risks for nonfatal heart problems and with ­obesity, which can also lead to heart trouble. But in the new study, obesity didn’t explain the link between sugary diets and death. That link was found even in normal-weight people who ate lots of added sugar.

The researchers focused on sugar added to processed foods or drinks, or sprinkled in coffee or cereal. Even foods that don’t taste sweet have added sugar, including many brands of packaged bread, tomato sauce and salad dressing. Naturally occurring sugar, in fruit and some other foods, wasn’t counted.

Researchers used data from the National Health and Nutrition Examination Survey, or NHANES — a large study updated each year by the CDC — to measure changes in sugar consumption over time and to see its health effects. Added sugars were defined as “all sugars used in processed or prepared foods, such as sugar-sweetened beverages, grain-based desserts, fruit drinks, dairy desserts, candy, ready-to-eat cereals, and yeast breads, but not naturally occurring sugars, such as in fruits and fruit juices.”

Between 1988 and 1994, Americans got 15.7 percent of their calories from added sugars, on average. That figure rose to 16.8 percent from 1999 to 2004, then fell to 14.9 percent between 2005 and 2010, the researchers found.

In the most recent period studied, about 10 percent of adults got more than 25 percent of their calories from added sugar. Nonsmokers, blacks and people younger than 60 ate and drank more added sugar than other adults.

For the second part of the study, the research team took a close look at 11,733 people who were part of NHANES between 1988 and 2006 and tracked for a median of 14.6 years. During those years, 831 people died as a result of cardiovascular disease.

Study participants were divided into five groups based on their sugar consumption. People in the lowest group got fewer than 9.6 percent of their calories from added sugars, while those in the highest group got more than 21.3 percent of their calories from added sugars, the researchers found.

And as sugar intake increased, risks climbed steeply.

Soda pop is No. 1 source

Compared with the people in the lowest group, those in the highest group were more than twice as likely to die during the follow-up period, according to the study. But they weren’t the only ones who put their health in jeopardy. People in the second-highest group of sugar consumption saw their risk of death due to cardiovascular disease (CVD) rise by 7 percent; those in the middle group saw their risk rise 18 percent, and those in the fourth-highest group had 38 percent greater odds of CVD death compared with the people in the baseline group.

All figures were adjusted for age, gender, race, income, smoking and drinking history, exercise habits, body mass index and diet quality, among other factors. The death risk increases were considered too large to be chance. In general, people who consumed more added sugar also had more fat and cholesterol in their diets, and they ate less meat, vegetables and grains, according to the study.

Soda and other types of sugar-sweetened beverages accounted for 37.1 percent of the sweeteners in U.S. diets. Those were followed by grain-based desserts (13.7 percent), fruit drinks (8.9 percent), dairy desserts (6.1 percent) and candy (5.8 percent).

In the past, experts focused on obesity and cavities as the main health problems from sugars. But recent studies have linked the sweeteners directly to high blood pressure, high cholesterol, cardiovascular disease, diabetes, liver cirrhosis and dementia, Laura Schmidt, a professor of health policy at the University of California, San Francisco, School of Medicine, wrote in a commentary with the study.

Another complication is that there is no specific national guideline for sugar consumption. The Institute of Medicine recommends sugar be less than 25 percent of total calories, the World Health Organization recommends less than 10 percent, while the American Heart Association suggests limiting sugar to less than 150 calories a day for men and less than 100 calories a day for women.

Colleen Kelly

Gallery: How much sugar is hidden in our food?

Dr. Jonathan Purnell, a professor at Oregon Health & Science University’s Knight Cardiovascular Institute, said while the research doesn’t prove “sugar can cause you to die of a heart attack,” it adds to a growing body of circumstantial evidence suggesting that limiting sugar intake can lead to healthier, longer lives.

The new study, Schmidt wrote, “holds potential to turn the political tide by demonstrating that added sugar is not as benign as once promised.”

Sure, holiday baking traditions are great. But isn't it time to try a new sweet treat this year? The Holiday Cookie Finder has every winning recipe from our annual baking contest from the past 14 years.

It's tempting to drop everything and roam Minnesota to catch all the crimsons and golds at this time of year. But who has time for that? We've found your leaf-peeping match. Just follow our flow chart.